drm/xe/queue: fix engine_class bounds check

drm/xe/queue: fix engine_class bounds check

The engine_class is the index into the user_to_xe_engine_class,
therefore it needs to be less than.

Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Signed-off-by: Matthew Auld <[email protected]>
Cc: Nirmoy Das <[email protected]>
Reviewed-by: Nirmoy Das <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
(cherry picked from commit fe87b7dfcb204a161d1e38b0e787b2f5ab520f32)
Signed-off-by: Lucas De Marchi <[email protected]>